" The language we speak, the beliefs we hold-both good and bad-are passed from generation to generation through experience. And so many aspects of the human experience are invented-as opposed to simply springing up from our genes. Ten thousand years ago, humankind had the genetic potential to read a book, yet not one single human on the planet could read; the genetic potential to play the piano existed, yet not one person could play; the genetic potential to dunk a basketball, type a sentence, ride a bicycle-all that potential existed, but it all remained unexpressed. Humankind, more than any other species, can take the accumulated, distilled experiences of previous generations and pass these inventions, beliefs, and skills to the next generation. This is sociocultural evolution. We learn from our elders, and we invent, and we pass what we’ve learned and invented to the next generations. And the organ that allows this is the human brain-specifically, the cortex. As we’ve said before, the cortex is the most uniquely human part of our body, and, no surprise, it gives rise to the most uniquely human capabilities: speech, language, abstract thinking, reflecting on the past, planning for the future. Our hopes, dreams, and a major part of our worldview are mediated by our cortex. "

― Bruce D. Perry , What Happened To You?: Conversations on Trauma, Resilience, and Healing